A method of this type may be used for planning and predicting traffic that is generated in a coverage area of a cellular radio network, particularly a digital radio network such as, for example, a radio network, which is based on the GSM or UMTS standard. The basis for the generation of a useable traffic database is an assignment of customers who are moving in the area, such as e.g., mobile radio units, to a radio network radio cell serving them, or to a base station located in this radio cell, in a manner that is matched to the real conditions as closely as possible. A simplified method for this, which is based on the application of a field strength prediction model for each radio cell, is known from the presentation “Radio Network Planning with EDGE” by Dr. Bernd Pfeiffer, which was given at the IBC Conference “EDGE”, June 2001 Dublin. The radio cell is defined in this method by a coverage area in which the base station that is located therein acts as a so-called “best server”. According to this best-server model, an allocation or assignment of a certain area element within a radio network to a radio cell or to a base station located therein is uniquely defined. As long as a customer is located within the thus uniquely defined coverage area of a certain radio cell, he is served by the so-called best server. Outside this coverage area, he is automatically served uniquely defined by an adjoining or other radio cell, the base station of which then acts as the best server. This means that, under the best-server model, there is no overlap or correlation with respect to the service for a customer who is located in the radio network. The radio cells are uniquely separated from each other and at the same time immediately adjacent, so that the assignment of a customer, such as a mobile radio unit, moving within the same to a radio cell is always uniquely defined.
In contrast to the above, it is known from the presentation “Achieving the Optimal Mix of relevant and reliable input data for interference analysis and automatic frequency planning” by Dr. Bernd Pfeiffer, given at the IIR Conference “The frequency planning technical forum”, May 1998, London, in deviation from the simplified, above-mentioned best-server model, to allow for correlations with respect to the coverage of an area element on the part of adjoining radio cells within a radio network by using so-called assignment probabilities of the area element, or of a customer located within the area element, such as, e.g., a mobile radio unit, to the individual radio cells. This is done by assigning a certain probability to each area element within the radio network, with which a subscriber located in this area element, such as, e.g., a mobile radio unit, is served or covered by a certain radio cell. As long as the mobile radio unit is located at an area element within this radio network, the sum of the assignment probabilities over all radio cells belonging to the radio network is smaller than or equal to one. If the sum of the assignment probabilities at an area element is smaller than one, this means that the respective area element is no longer fully covered by the radio network. This situation exists at the edge of the network and in coverage gaps of the radio network. If the sum of the assignment probabilities at an area element within the radio network is equal to one, it is certain that the subscriber is receiving service at the respective area element from at least one radio cell. However, compared to the above-described best-server model, it is not uniquely defined by which radio cell the subscriber is served; instead, a prediction can be made here only with the above-mentioned assignment probability.
While the so-called best-server radio cell model, which assigns exactly one radio cell to each area element, can be described as discrete, the use of a so-called continuous radio cell model has the effect that each area element of the radio network can be assigned a radio cell only with a certain probability.
Particularly when examining so-called multi-layer radio networks, the best-server model is overly simplified for a generation of a space-related traffic database, since a uniquely defined allocation or assignment of a radio cell to an area element does not appear very realistic in this case because of the multiple layers, which are generated, for example, by overlays of multiple radio networks.
It was accordingly an object of the present invention, proceeding from the best-server model, to make available a method whereby it is possible to generate a space-related traffic database also in the case of a multi-layer radio network, with the aid of which a prediction of traffic being generated at the area elements in the radio network is made possible.